Your toddler can't tell other kids to back off or leave her alone with words, so she's likely to use her hands to defend herself. If you find that your toddler is pushing or acting aggressively toward other kids, you'll need to intervene. With firm guidance and consistent expectations, you can teach your toddler how to handle herself diplomatically when she gets mad or frustrated. It's a skill that takes practice, but with time, she'll get it.
Keep your cool when your tot lashes out. Getting mad yourself will only reinforce the negative behavior. Model chilled-out behavior and your tot is likely to follow your example.
Help the pushed child to make sure she’s alright. Comfort her and give her a hug to ease the injured feelings. By letting your toddler see you comfort the victim, you withhold negative reinforcement for the pushing behavior -- in other words, you don't reward his aggression with negative attention.
Kneel down in front of your toddler, look him in the eye and calmly tell him, “No pushing. You pushed Ingrid and hurt her. We don’t push.” Keep your sentences simple so he understands you.
Figure out what precipitated the aggression and try to resolve it. For example, if you find out that the victim took a toy and frustrated your toddler, talk about it with the little ones. You might say, “We don’t push each other. Ingrid, would you please give James back the ball you took from him. When he’s done playing with the ball, it will be your turn.”
Supervise the play to make sure nothing else happens. If you get a clue that more problems are coming, remove your toddler and get him busy with independent play under your guidance.